Livestock

Livestock are animals bred in captivity by humans to serve a variety of useful purposes. In the most general sense of the word it can include any farm animal raised for pleasure or profit, even including dogs and butterflies [1]. But in common agricultural usage it usually refers to large hooved mammals. Birds are usually classified in the related category of poultry. The process of raising and breeding livestock is known as animal husbandry and is an important component of modern agriculture. The raising of livestock can be traced to the beginnings of human civilization, when instead of hunting wild animals, humans began to capture animals for breeding.

Throughout history, livestock have been considered to be a form of wealth. Livestock are mentioned in many parts of the Bible and were used as forms of trade and given as gifts. For example, in the Book of Genesis, Jacob gave the following as a peace offering to his estranged brother Esau: "Two hundred female goats, twenty male goats, two hundred ewes, twenty rams, thirty milk camels with their colts, forty cows, ten bulls, twenty female donkeys and ten foals." Livestock were also offered as sacrifices to atone for sin.

For reasons to be discussed below, most forms of livestock are herbivorous mammals. Various types of livestock are reared depending on the local conditions: climate, land type, native animals and tradition all influence the predominant type of livestock in any given area.

Uses

Historically, livestock has benefited humanity in five main ways:

Meat - In many agricultural societies, livestock replaced wild game as the primary source of animal protein. Livestock frequently eat vegetation and other food sources that humans cannot eat, and convert them to types of food that humans can eat.
Dairy products - Mammalian livestock can be used a source of milk, which can in turn be processed into other dairy products such as yogurt, cheese, butter, ice cream, kefir, and kumiss. Using livestock for this purpose can often yield several times the calories of slaughtering the animal outright.
Useful materials - A variety of useful materials are produced by livestock. Some animals, such as sheep, grow thick coats that can be shorn and used in textiles. Other animals, such as cows, have a tough skin which upon slaughtering can be made into leather. The bones and horns of livestock have also been employed in a variety of industrial, cultural and decorative uses.
Fertilizer - Livestock leave behind manure, which, after being spread on a field, can increase crop yields many times. This is an important reason why historically, plant and animal domestication have been intimately linked.
Labour - Livestock often serves as an important source of mechanical energy. Before the advent of steam power, livestock was often the only source of non-human labour available. Livestock can be used to pull ploughs and other agricultural equipment (again increasing farm yields), transport goods across large distances, and also serve important military functions.

Types of livestock

NOTE: The information below deals with the use of certain animals in the specific area of livestock. For more general information on these animals, such as their biology, evolution, habitat, etc, please see their corresponding main articles.

Animal / Type	Wild ancestor	Domesticated	Area first domesticated	Current range	Uses
Alpaca Mammal, herbivore	Guanaco		Andes	Andes, North America	wool
Bison Mammal, herbivore	Wild buffalo	Late 19th Century	North America	North America, Australia	meat, leather, dairy
Camel Mammal, herbivore	Wild Dromedary and Bactrian camels	Between 4000 BCE and 1400 BCE	Asia	Africa, Asia, Australia	Labour, dairy
Cow Mammal, herbivore	Auroch (extinct)	6000 BCE	Southwest Asia, India, North Africa (?)	Worldwide	Meat (beef, veal), dairy, leather, labour
Deer Mammal, herbivore	Wild deer		North America	North America, Australia	antler velvet, antlers, meat (venison), leather
Donkey Mammal, herbivore	Wild ass	4000 BCE	Egypt	Worldwide	Labour, meat
Goat Mammal, herbivore	Bezoar goat	8000 BCE	Southwest Asia	Worldwide	Dairy, meat, wool
Horse Mammal, herbivore	Wild horses of Southern Russia (extinct)	4000 BCE	Ukraine	Worldwide	Labour, military, meat, dairy (rare)
Llama Mammal, herbivore	Guanaco	3500 BCE	Andes	Andes, North America	Labour, meat, wool
Mule Mammal, herbivore	Sterile hybrid of donkey and horse			Worldwide	Labour
Pig Mammal, omnivore	Wild boar	8000 BCE	Southwest Asia, China	Worldwide	Meat (pork), leather
Rabbit Mammal, herbivore	Wild rabbit	between 400-900 CE	France	Worldwide	Meat, wool
Reindeer Mammal, herbivore	Wild reindeer	3000 BCE	Russia	Arctic	Meat, leather, antlers, labour
Sheep Mammal, herbivore	Asiatic mouflon sheep	8000 BCE	Southwest Asia	Worldwide	Wool, dairy, meat (mutton, lamb)
Water buffalo Mammal, herbivore	Wild water buffalo	4000 BCE	China (Tibetan Plateau)	Tibetan Plateau	Labour, meat, dairy
Yak Mammal, herbivore	Wild yak		Tibet	Tibetan plateau	Meat, dairy, wool, labour

Prerequisites for livestock

Given that there are over a hundred large land based mammals, it may be surprising that so few types were domesticated into livestock. The reason for this relative paucity is that most mammals do not meet one or more of the basic prerequisites necessary for domestication:

Diet - In order to be domesticated, a given animal must have a widely available food source. In biological processes, the conversion of food into biomass is normally accomplished at only a 10% rate of efficiency, that is, it takes 10,000 pounds of corn to raise a 1,000 pound cow. Assuming that carnivores have the same 10% efficiency, this rules out raising most large carnivorous mammals as livestock as the 1000 pounds of cow would only produce 100 pounds of carnivore meat. A possible exception, the dog, is only very rarely used for food, and is normally raised for other reasons.
Reproduction - The animal in question must be able to breed in captivity at a sufficient rate. This rules out slow reproducing animals such as the elephant, and animals which do not breed well in captivity, such as the cheetah (which, when tamed, was superior to the dog as a hunting companion).
Safety - The dispositions of certain animals, such as the zebra, make them almost impossible to domesticate. Some pack animals are also prone to panic and stampedes, also inhibiting attempts to raise them in captivity.
Social structure - Since breeding animals in captivity requires many organisms of the same species to be in a relatively confined area, solitary animals are difficult, if not impossible, to raise as livestock. Herd animals, on the other hand, are better suited - the wild ancestors of cows, sheep, horses, etc, all lived in herds.
Low toxicity - Some poisons are collected during food consumption and are not released from the body. Such poisons are accumulated in increasing amounts in species that are further up the food chain. For example, insecticides sprayed on plants won't kill the plant nor the mice eating the plants. A lion eating those mice might be killed by the accummulation of the insecticides taken in by its prey.

Disease

Livestock constitute a major source of epidemic diseases – these diseases have had a significant impact on history. When an agricultural society which raises livestock comes in contact with a non-agricultural society, often diseases spread to the latter group (who lack any resistance), which can have devastating consequences.

The following table lists diseases which originally infected livestock and can now infect humans:

Disease	Source animal
Smallpox	Cattle
Tuberculosis	Cattle
Measles	Cattle
Influenza	Pigs, ducks
Pertussis	Pigs, dogs

Other diseases can be transmitted from animals. Mad cow disease is transmitted between cattle which eat food containing cattle brains and spines. It can also be transmitted to humans who eat infected cattle. This disease has led to a ban on using cattle by-products in cattle feed. Anthrax was called the woolsorter's disease because the skin form of the disease could be contracted from handling raw wool.

The use of antibiotics in animals that end up in the human food chain is controversial. The issue of antibiotic resistance has limited the practices of preventative dosing such as antibiotic-laced feed.

Livestock are also subject to other diseases. Veterinary certificates are often required before transporting, selling, or showing animals. Disease-free areas are often rigorously enforced. Foot and mouth disease (FMD) led to a massive government sheep and cattle kill in the north of England in 2001. Six million animals were killed to stop an outbreak with 2,000 confirmed cases. Bison which wander out of Yellowstone National Park are routinely shot to prevent the possible spread of brucellosis to Montana cattle.

Farming practices

At the most basic level, animals are kept in enclosures of some sort, are fed by some means (given access to natural or human-provided sources of food), are usually bred (preferred breeding times, methods, etc. all depend on local conditions and tradition) and are either slaughtered for meat and animal by-products, or are milked or shorn for animal by-products.

Livestock may be kept in confinement in very small areas as with rabbits or veal cattle, in fenced pastures, or on large open ranges where they are only occasionally collected in "round-ups". Herding dogs such as sheep dogs and cattle dogs may be used for this as are cowboys on horseback or sometimes in helicopters. Since the advent of barbed wire and electric fencing technology, fencing pastures has become much more feasible. In some cases, very large numbers of animals may be kept in indoor or outdoor feeding operations, where the animals' feed is processed and stored on site and then fed to the animals. Because of their size, the quantity of waste involved, fly and odor problems, potential for groundwater contamination, and other factors, these facilities are highly regulated and are controversial in some areas.

See: factory farming, feedlot, hog lot

Livestock may be branded, marked, or tagged to denote ownership or for inventory, breeding, health management, or other purposes.

Modern farming techniques mainly focus on the automation of the various tasks involved, and intervention to increase yield or animal health. Successive improvements of traditional techniques have mostly focused on these same goals. Economics, quality, and consumer safety all play a role in how animals are raised. Drug use, and feed supplements (or even feed type) may be regulated, to ensure yield is not increased at the expense of consumer health or safety. Practices vary around the world, for example, growth hormone use is permitted in the United States, but not in the European Union (or countries selling meat/produce in the EU).

Stock shows and fairs

Stock shows and fairs are events where people bring their best livestock to compete with one another. Organizations like 4-H and Future Farmers of America (FFA) encourage young people to raise livestock for show purposes. Special feeds are purchased and hours may be spent prior to the show grooming the animal to look its best. In cattle, sheep, and swine shows, the winning animals are frequently auctioned off to the highest bidder and the funds placed into a scholarship fund for its owner.

Livestock transportation and marketing

Since many livestock are herd animals, they were historically driven to market "on the hoof" to a town or other central location. During the period after the American Civil War, the abundance of Longhorn cattle in Texas and the demand for beef in Northern markets led to the popularity of the Old West cattle drive. This method is still used in some parts of the world. Truck transport is now common in developed countries. Local and regional livestock auctions and commodity markets facilitate trade in livestock. In other areas livestock may be bought and sold in a bazaar or flea market type setting such as the First Monday Trade Days in Canton, Texas.

External links